Add gundo plugin to vim via git submodules

.gitmodules

@@ -4,3 +4,6 @@
 [submodule ".vim/bundle/pathogen"]
 	path = .vim/bundle/pathogen
 	url = http://github.com/tpope/vim-pathogen.git
+[submodule ".vim/bundle/gundo"]
+	path = .vim/bundle/gundo
+	url = http://github.com/sjl/gundo.vim

.vim/bundle/gundo

@@ -0,0 +1 @@
+Subproject commit 12b6f67aeb892519385529b2b5cdda55cc428d9d